Plot Screenshots: Sinc Scatter Demo
customPlot->legend->setVisible(true);
customPlot->legend->setFont(QFont("Helvetica",9));
// set locale to english, so we get english decimal separator:
customPlot->setLocale(QLocale(QLocale::English, QLocale::UnitedKingdom));
// add confidence band graphs:
customPlot->addGraph();
QPen pen;
pen.setStyle(Qt::DotLine);
pen.setWidth(1);
pen.setColor(QColor(180,180,180));
customPlot->graph(0)->setName("Confidence Band 68%");
customPlot->graph(0)->setPen(pen);
customPlot->graph(0)->setBrush(QBrush(QColor(255,50,30,20)));
customPlot->addGraph();
customPlot->legend->removeItem(customPlot->legend->itemCount()-1); // don't show two confidence band graphs in legend
customPlot->graph(1)->setPen(pen);
customPlot->graph(0)->setChannelFillGraph(customPlot->graph(1));
// add theory curve graph:
customPlot->addGraph();
pen.setStyle(Qt::DashLine);
pen.setWidth(2);
pen.setColor(Qt::red);
customPlot->graph(2)->setPen(pen);
customPlot->graph(2)->setName("Theory Curve");
// add data point graph:
customPlot->addGraph();
customPlot->graph(3)->setPen(QPen(Qt::blue));
customPlot->graph(3)->setLineStyle(QCPGraph::lsNone);
customPlot->graph(3)->setScatterStyle(QCPScatterStyle(QCPScatterStyle::ssCross, 4));
// add error bars:
QCPErrorBars *errorBars = new QCPErrorBars(customPlot->xAxis, customPlot->yAxis);
errorBars->removeFromLegend();
errorBars->setAntialiased(false);
errorBars->setDataPlottable(customPlot->graph(3));
errorBars->setPen(QPen(QColor(180,180,180)));
customPlot->graph(3)->setName("Measurement");
// generate ideal sinc curve data and some randomly perturbed data for scatter plot:
QVector<double> x0(250), y0(250);
QVector<double> yConfUpper(250), yConfLower(250);
for (int i=0; i<250; ++i)
{
x0[i] = (i/249.0-0.5)*30+0.01; // by adding a small offset we make sure not do divide by zero in next code line
y0[i] = qSin(x0[i])/x0[i]; // sinc function
yConfUpper[i] = y0[i]+0.15;
yConfLower[i] = y0[i]-0.15;
x0[i] *= 1000;
}
QVector<double> x1(50), y1(50), y1err(50);
for (int i=0; i<50; ++i)
{
// generate a gaussian distributed random number:
double tmp1 = rand()/(double)RAND_MAX;
double tmp2 = rand()/(double)RAND_MAX;
double r = qSqrt(-2*qLn(tmp1))*qCos(2*M_PI*tmp2); // box-muller transform for gaussian distribution
// set y1 to value of y0 plus a random gaussian pertubation:
x1[i] = (i/50.0-0.5)*30+0.25;
y1[i] = qSin(x1[i])/x1[i]+r*0.15;
x1[i] *= 1000;
y1err[i] = 0.15;
}
// pass data to graphs and let QCustomPlot determine the axes ranges so the whole thing is visible:
customPlot->graph(0)->setData(x0, yConfUpper);
customPlot->graph(1)->setData(x0, yConfLower);
customPlot->graph(2)->setData(x0, y0);
customPlot->graph(3)->setData(x1, y1);
errorBars->setData(y1err);
customPlot->graph(2)->rescaleAxes();
customPlot->graph(3)->rescaleAxes(true);
// setup look of bottom tick labels:
customPlot->xAxis->setTickLabelRotation(30);
customPlot->xAxis->ticker()->setTickCount(9);
customPlot->xAxis->setNumberFormat("ebc");
customPlot->xAxis->setNumberPrecision(1);
customPlot->xAxis->moveRange(-10);
// make top right axes clones of bottom left axes. Looks prettier:
customPlot->axisRect()->setupFullAxesBox();